Fluorobenzyl esters

ABSTRACT

Fluorobenzyl esters of the formula: ##STR1## wherein X represents the residue of any carboxylic acid of formula X-COOH which forms an insecticidally active ester with a 3-phenoxybenzyl alcohol, and R, R 6  and R 7  are each selected from hydrogen, halogen and alkyl of up to four carbon atoms, provided that at least one of R, R 6  and R 7  represents halogen, and further provided that R and R 6  are not both bromine when R 7  is hydrogen. The compounds are useful for combatting insect and acarine pests.

This is a continuation of application Ser. No. 07/133,665, filed on Dec.14, 1987, which was abandoned upon the filing hereof.

This invention relates to novel fluorobenzyl esters useful asinsecticides and acaricides, to insecticidal and acaricidal compositionscomprising them, to processes and intermediates for their preparationand to methods of combating insect, acarine and similar invertebratepests using them.

The novel fluorobenzyl esters of this invention have the generalformula: ##STR2## wherein X represents the residue of any carboxylicacid of formula X--COOH which forms an insecticidally active ester witha 3-phenoxybenzyl alcohol, and R, R⁶ and R⁷ are each selected fromhydrogen, halogen and alkyl of up to four carbon atoms, provided that atleast one of R, R⁶ and R⁷ represents halogen, and further provided thatR and R⁶ are not both bromine when R⁷ is hydrogen. More particularly Xrepresents either:

(a) a group of formula: ##STR3## wherein (i) R¹ and R² are each selectedfrom hydrogen, halo and alkyl of up to four carbon atoms, or (ii) R¹ ishydrogen and R² represents either a group of formula: ##STR4## or agroup of formula: ##STR5## where R³ and R⁴ are each selected frommethyl, halo, or haloalkyl of one or two carbon atoms containing atleast two fluorine atoms, and Y is chloro or bromo; or

(b) X represents a group of formula: ##STR6## where R⁵ represents analkyl group of up to four carbon atoms and Ar represents a phenyl groupoptionally substituted with one or two halogen atoms.

Preferred compounds according to the invention are those of formula IA:##STR7## wherein R, R⁶ and R⁷ have any of the meanings givenhereinabove, and R¹ and R² are each selected from halogen and alkyl ofup to four carbon atoms (preferably methyl), or R¹ is hydrogen and R² isa group of formula: ##STR8## wherein R³ and R⁴ are each selected frommethyl, fluoro, chloro, bromo and trifluoromethyl.

Particularly preferred compounds according to formula IA are those setout in Table I below wherein the meaning of R, R¹, R², R⁶ and R⁷ are setout for each compound.

                  TABLE I                                                         ______________________________________                                        COMPOUND   R     R.sup.6                                                                             R.sup.7                                                                            R.sup.1                                                                            R.sup.2                                      ______________________________________                                         1         H     Cl    H    CH.sub.3                                                                           CH.sub.3                                      2         H     Cl    H    H    --CH = C(CH.sub.3).sub.2                      3         H     Cl    H    H    --CH = CCl.sub.2                              4         H     Cl    H    H    --CH = CBr.sub.2                              5         H     Cl    H    H    --CH = CF.sub.2                               6         H     Cl    H    H    --CH = C(F)CF.sub.3                           7         H     Cl    H    H    --CH = C(Cl)CF.sub.3                          8         H     Cl    H    H    --CH = C(Br)CF.sub.3                          9         H     Cl    H    H    --CH = C(CF.sub.3).sub.2                     10         H     Cl    H    Cl   Cl                                           11         H     H     F    H    --CH = C(Cl)CF.sub.3                         12         Br    H     Br   H    --CH(Br)--C(Br)Cl.sub.2                      13         Br    H     Br   H    --CH = C(Cl)CF.sub.3                         14         Cl    Cl    H    H    --CH = C(Cl)CF.sub.3                         15         H     H     Cl   H    --CH = C(Cl)CF.sub.3                         16         H     H     Br   H    -- CH = C(Cl)CF.sub.3                        17         Br    H     H    H    --CH = C(Cl)CF.sub.3                         18         Cl    H     CH.sub.3                                                                           H    --CH = C(Cl)CF.sub.3                         19         Cl    H     Cl   H    --CH = C(Cl)CF.sub.3                         20         Cl    H     Cl   H    --CH = C(F)CF.sub.3                          21         Cl    H     Cl   H    --CH = CCl.sub.2                             22         Cl    H     Cl   CH.sub.3                                                                           CH.sub.3                                     ______________________________________                                    

It will be appreciated that certain of the compounds of the inventionwherein R¹ and R² are not identical are capable of existing in more thanone isomeric form, due to the possibility of cis and trans isomerism inthe substitution pattern of the cyclopropane ring and the presence ofchiral centres at C₁ and C₃ of the cyclopropane ring. Thus there may be(+)-cis, (-)-cis, (+)-trans and (-)-trans isomers. Where R² represents agroup of formula --CH═C(R³)R⁴ and R³ and R⁴ are not identical, thereexists the further possibility of E and Z isomers of the group R². Inaddition, there is the still further possibility of E and Z isomers inthe alcohol moiety of the invention compounds according to certaincombinations of the values of R, R⁶ and R⁷. The scope of the inventionincludes each of the said isomeric forms in isolation as well asmixtures thereof, including racemic mixtures.

Examples of the preferred compounds according to formula IA include

4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product I)

4-(2-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product II)

4-(2-fluoroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product III)

4-(EZ-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 2:1, Product IV; E:Z ratio of alcoholmoiety 1:9, Product VI)

4-(E-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product V)

4-(EZ-3-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 3:1, Product VII)4-(EZ-3-chloro-2-methylprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 1:4, Product VIII)

4-(3,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product IX)

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product X)

4-(E-2,3-dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product XI)

4-(E-2,3-Dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-[(RS)-1,2-dibromo-2,2-dichloroethyl]-2,2-dimethylcyclopropanecarboxylate(Product XII)

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product XIII)

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate(Product XIV)

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate(Product XV)

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl2,2,3,3-tetramethylcyclopropanecarboxylate (Product XVI)

4-(EZ-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate

4-(EZ-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2,3,3,3-tetrafluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(Z-2,3,3,3-tetrafluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

4-(EZ-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2,3,3,3-tetrafluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate4-(EZ-3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(Z-2,3,3,3-tetrafluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate

The compounds of the invention are esters and may be prepared byconventional esterification processes, of which the following areexamples.

(a) An acid of formula (II)

    X----COOH                                                  (II)

where X has any of the meanings given hereinabove, may be reacteddirectly with a 4-haloalkenyl-2,3,5,6-tetrafluorobenzyl alcohol offormula (III): ##STR9## where R, R⁶ and R⁷ have any of the meaningsgiven hereinabove, the reaction preferably taking place in the presenceof an acid catalyst, for example, dry hydrogen chloride, or adehydrating agent, for example, a carbodiimide such asN,N'-dicyclohexylcarbodiimide.

(b) An acid halide of formula X--COHal where Hal represents a halogenatom, preferably a chlorine atom, and X has any of the meanings givenhereinabove, may be reacted with the alcohol of formula (III), thereaction preferably taking place in the presence of a base, for example,pyridine, a trialkylamine, or an alkali metal hydroxide or carbonate.

(c) An acid of formula (II) where X has any of the meanings givenhereinabove, or preferably, an alkali metal salt thereof, may be reactedwith a halide of formula (IV): ##STR10## where Hal represents a halogenatom, preferably the bromine or chlorine atom, and R, R⁶ and R⁷ have anyof the meanings given hereinabove, or with the quaternary ammonium saltsderived from such halides by reaction with tertiary amines, for examplepyridine, or a trialkylamine such as triethylamine.

(d) A lower alkyl ester of formula X--COOQ where Q represents a loweralkyl group containing up to six carbon atoms, preferably the methyl orethyl group, and X has any of the meanings given hereinabove, is heatedwith the alcohol of formula (III) to effect a transesterificationreaction. Preferably the process is performed in the presence of asuitable catalyst, for example, an alkali metal alkoxide, such as sodiummethoxide, or an alkylated titanium derivative, such as tetramethyltitanate or tetraethyl titanate.

All of these conventional processes for the preparation of esters may becarried out using solvents and diluents for the various reactants whereappropriate, and may be accelerated or lead to higher yields of productwhen performed at elevated temperatures or in the presence ofappropriate catalysts, for example phase-transfer catalysts.

The preparation of individual isomers may be carried out in the samemanner but commencing from the corresponding individual isomers of thecompounds described in (a) to (d) above. These may be obtained byconventional isomer separation techniques from mixtures of isomers.Thus, for example, cis and trans isomers of the compounds of formula(II) may be separated by fractional crystallisation of the carboxylicacids or salts thereof, whilst the various optically active species maybe obtained by fractional crystallisation of salts of the acids withoptically active amines, followed by regeneration of the optically pureacid. The optically pure isomeric form of the acid (or its equivalentacid chloride or ester) may then be reacted with the alcohol of formula(III) to produce a compound of formula (I) in the form of anindividually pure isomer thereof.

4-Haloalkenyl-2,3,5,6-tetrafluorobenzyl alcohols (III) have not beendescribed previously. In a further aspect therefore the inventionprovides 4-haloalkenyl-2,3,5,6-tetrafluorobenzyl alcohols of formula(III), wherein R, R⁶ and R⁷ have any of the meanings given above, asnovel intermediates useful in the preparation of the insecticidal estersof the invention. Specific examples of the alcohols of formula (III)according to this invention include those for which values of R, R⁶ andR⁷ are listed in Table II, and stereoisomers thereof, where geometricisomerism is possible.

                  TABLE II                                                        ______________________________________                                        Compound       R        R.sup.6   R.sup.7                                     ______________________________________                                        A              H        H         Cl                                          B              H        H         Br                                          C              H        H         F                                           D              H        Cl        H                                           E              Br       H         H                                           F              Cl       H         CH.sub.3                                    G              Cl       Cl        H                                           H              Br       H         Br                                          J              Cl       H         Cl                                          ______________________________________                                    

These compounds may be prepared from a derivative of a4-halo-2,3,5,6-tetrafluorobenzylalcohol in which the hydroxy functionhas been reversibly protected, and an appropriately substitutedhalopropene of formula (V): ##STR11## where R, R⁶ and R⁷ have any of themeanings described hereinabove and X represents a halogen of at leastthe same, and preferably greater atomic weight than the halogen ofhighest atomic weight represented by R, R⁶ or R⁷, in the presence of analkyllithium, preferably n-butyllithium, and a cuprous halide catalyst,followed by deprotection of the hydroxy function; this method isillustrated, by way of example only, in Scheme I. ##STR12## Where R ishydrogen or alkyl of up to four carbon atoms and either both of R⁶ andR⁷ are chlorine or both of R⁶ and R⁷ are bromine, the alcohols offormula (III) may alternatively be prepared by the addition reactionbetween a derivative of a compound of formula (VI): ##STR13## wherein Rrepresents hydrogen or alkyl of up to four carbon atoms, in which thehydroxy function has been reversibly protected, and an equimolarquantity of a halogen selected from chlorine and bromine. Halogenaddition may alternatively be achieved by reaction between the compoundof formula (VI) and a cupric halide-lithium halide mixture selected fromcupric chloride-lithium chloride and cupric-bromide-lithium bromide.These methods are illustrated, by way of example only, in Scheme II.##STR14##

Further details concerning the preparation and characterisation of thecompounds of the invention are given hereinafter in the Examples.

The compounds of formula (I) may be used to combat and controlinfestations of insect and acarine pests. The insect and acarine pestswhich may be combated and controlled by the use of the inventioncompounds include those pests associated with agriculture (which termincludes the growing of crops for food and fibre products, horticultureand animal husbandry), forestry, the storage of products of vegetableorigin, such as fruit, grain and timber, and also those pests associatedwith the transmission of diseases of man and animals.

In order to apply the compounds to the locus of the pests they areusually formulated into compositions which include in addition to theinsecticidally active ingredient or ingredients of formula (I) suitableinert diluent or carrier materials, and/or surface active agents.

The compounds of the invention may be the sole active ingredient of thecomposition or they may be admixed with one or more additional activeingredients such as insecticides, insecticide synergist, herbicides,fungicides or plant growth regulators where appropriate.

Suitable additional active ingredients for inclusion in admixture withthe compounds of the invention may be compounds which will broaden thespectrum of activity of the compounds of the invention or increase theirpersistence in the location of the pest. They may synergise the activityof the compounds of the invention or complement the activity for exampleby increasing the speed of effect, improving knockdown or overcomingrepellency. Additionally multi-component mixtures of this type may helpto overcome or prevent the development of resistance to individualcomponents.

The particular insecticide, herbicide or fungicide included in themixture will depend upon its intended utility and the type ofcomplementary action required. Examples of suitable insecticides includethe following:

(a) Pyrethroids such as permethrin, esfenvalerate, deltamethrin,cyhalothrin, biphenthrin, fenpropathrin, cyfluthrin, tefluthrin, fishsafe pyrethroids for example ethofenprox, natural pyrethrins,tetramethrin, s-bioallethrin, fenfluthrin, prallethrin and5-benzyl-3-furylmethyl-(E)-(1R,3S)-2,2-dimethyl-3-(2-oxothiolan-3-ylidenemethyl)cyclopropanecarboxylate;

(b) Organophosphates such as profenofos, sulprofos, dichlorvos, methylparathion, azinphos-methyl, demeton-s-methyl, heptenophos, thiometon,fenamiphos, monocrotophos, profenophos, triazophos, methamidophos,dimethoate, phosphamidon, malathion, chlorpyrifos, phosalone,fensulfothion, fonofos, phorate, phoxim, pyrimiphos-methyl, fenitrothionand diazinon;

(c) Carbamates (including aryl carbamates) such as pirimicarb,cloethocarb, carbofuran, ethiofencarb, aldicarb, thiofurox, carbosulfan,bendiocarb, fenobucarb, propoxur and oxamyl;

(d) Benzoyl ureas such as triflumuron, chlorofluazuron;

(e) Organic tin compounds such as cyhexatin, fenbutatin oxide,azocyclotin;

(f) Macrolides such as avermectins or milbemycins, for example such asabamectin, avermectin, and milbemycin;

(g) Hormones and synthetic mimics thereof such as juvenile hormone,juvabione, ecdysones, methoprene and hydroprene.

(h) Pheromones.

(i) Organochlorine compounds such as benzene hexachloride, DDT,chlordane or dieldrin.

In addition to the major chemical classes of insecticide listed above,other insecticides having particular targets may be employed in themixture if appropriate for the intended utility of the mixture. Forinstance selective insecticides for particular crops, for examplestemborer specific insecticides for use in rice such as cartap orbuprofezin, can be employed. Alternatively insecticides specific forparticular insect species/stages for example ovolarvicides such asclofentezine, amitraz, chlordimeform, flubenzimine, hexythiazox andtetradifon, motilicides such as dicofol or propargite, adulticides suchas bromopropylate, chlorobenzilate, or insect growth regulators such ashydramethylon, cyromazine, methoprene, chlorofluazuron and diflubenzuronmay also be included in the compositions.

Examples of suitable insecticide synergists for use in the compositionsinclude piperonyl butoxide, sesamex, and dodecyl imidazole.

Suitable herbicides, fungicides and plant growth regulators forinclusion in the compositions will depend upon the intended target andthe effect required. An example of a rice selective herbicide which canbe included is propanil, an example of a plant growth regulator for usein cotton is "Pix", and examples of fungicides for use in rice includeblasticides such as blasticidin-S. The choice of other ingredients to beused in mixture with the active ingredient will often be within thenormal skill of the formulator, and will be made from known alternativesdepending upon the total effect to be achieved.

The ratio of the compound of the invention to any other activeingredient in the composition will depend upon a number of factorsincluding the type of insect pests to be controlled, and the effectsrequired from the mixture. However in general, the additional activeingredient of the composition will be applied at about the rate it wouldusually be employed if used on its own, or at a lower rate if synergismoccurs.

The compositions may be in the form of dusting powders wherein theactive ingredient is mixed with a solid diluent or carrier, for examplekaolin, bentonite, kieselguhr, or talc, or they may be in the form ofgranules, wherein the active ingredient is absorbed in a porous granularmaterial, for example pumice.

Alternatively the compositions may be in the form of liquid preparationsto be used as dips, sprays or aerosols. Dips and sprays are generallyaqueous dispersions or emulsions of the active ingredient in thepresence of one or more known wetting agents, dispersing agents oremulsifying agents (surface active agents). Aerosol compositions maycontain the active ingredient or ingredients, a propellant and an inertdiluent, for example odourless kerosene or alkylated benzenes. In apreferred form, aerosol compositions may contain from 0.005% to 4% ofactive ingredient or ingredients, the remainder of the compositioncomprising a solvent, selected from odourless kerosine and alkylatedbenzenes, and a propellant. Aerosol compositions may optionallyincorporate other additives, for example perfumes or corrosioninhibitors.

Wetting agents, dispersing agents and emulsifying agents may be of thecationic, anionic or non-ionic type. Suitable agents of the cationictype include, for example, quaternary ammonium compounds, for examplecetyltrimethyl ammonium bromide. Suitable agents of the anionic typeinclude, for example, soaps, salts of aliphatic monoesters or sulphuricacid, for example sodium lauryl sulphate, salts of sulphonated aromaticcompounds, for example sodium dodecylbenzenesulphonate, sodium, calciumor ammonium lignosulphonate, or butylnaphthalene sulphonate, and amixture of the sodium salts of diisopropyl- and triisopropylnaphthalenesulphonates. Suitable agents of the non-ionic type include, for example,the condensation products of ethylene oxide with fatty alcohols such asoleyl alcohol or cetyl alcohol, or with alkyl phenols such as octylphenol, nonyl phenol and octyl cresol. Other non-ionic agents are thepartial esters derived from long chain fatty acids and hexitolanhydrides, the condensation products of the said partial esters withethylene oxide, and the lecithins.

The compositions may be prepared by dissolving the active ingredient ina suitable solvent, for example, a ketonic solvent such as diacetonealcohol, or an aromatic solvent such as trimethylbenzene and optionallyadding the mixture so obtained to water which may contain one or moreknown wetting, dispersing or emulsifying agents.

Other suitable organic solvents are dimethyl formamide, ethylenedichloride, isopropyl alcohol, propylene glycol and other glycols,diacetone alcohol, toluene, kerosene, white oil, methylnaphthalene,xylenes and trichloroethylene, N-methyl-2-pyrrolidone andtetrahydrofurfuryl alcohol (THFA).

The compositions which are to be used in the form of aqueous dispersionsor emulsions are generally supplied in the form of a concentratecontaining a high proportion of the active ingredient or ingredients,the said concentrate to be diluted with water before use. Theseconcentrates are often required to withstand storage for prolongedperiods and after such storage, to be capable of dilution with water toform aqueous preparations which remain homogenous for a sufficient timeto enable them to be applied by conventional spray equipment. Theconcentrates may contain 1-99% by weight of the active ingredient oringredients. When diluted to form aqueous preparations such preparationsmay contain varying amounts of the active ingredient depending upon thepurpose for which they are to be used. For agricultural or horticulturalpurposes, an aqueous preparation containing between 0.0001% and 0.1% byweight of the active ingredient is particularly useful.

In use the compositions are applied to the pests, to the locus of thepests, to the habitat of the pests, or to growing plants liable toinfestation by the pests, by any of the known means of applyingpesticidal compositions, for example, by dusting or spraying.

The compositions of formula (I) and compositions comprising them arevery toxic to wide varieties of insect, acarine and other invertebratepests, including, for example, the following:

Myzus persicae (aphids)

Aphis fabae (aphids)

Megoura viceae (aphids)

Aedes aegypti (mosquitos)

Anopheles spp. (mosquitos)

Culex spp. (mosquitos)

Dysdercus fasciatus (capsids)

Musca domestica (houseflies)

Pieris brassicae (white butterfly, larvae)

Plutella maculipennis (diamond back moth, larvae)

Phaedon cochleariae (mustard beetle)

Aonidiella spp. (scale insects)

Trialeuroides spp. (white flies)

Blattella germanica (cockroaches)

Periplaneta americana (cockroaches)

Blatta orientalis (cockroaches)

Spodoptera littoralis (cotton leaf worm)

Heliothis virescens (tobacco budworms)

Chortiocetes terminifera (locusts)

Diabrotica spp. (rootworms)

Agrotis spp. (cutworms)

Chilo partellus (maize stem borers)

Nilaparvata lugens (plant hoppers)

Nephotettix cincticeps (leaf hoppers)

Panonychus ulmi

Panonychus citri

Tetranychus urticae (red spider mite)

Tetranychus cinnabarinus (carmine spider mite)

The compounds according to formula (I) and compositions comprising themhave been shown to be particularly useful in controlling lepidopteranpests of cotton, for example Spodoptera spp. and Heliothis spp., acarinepests such as Tetranychus spp. and Panonychus spp., and public healthpests such as flies and mosquitos. They have also been shown to beparticularly useful in combating pests which inhabit the soil, forexample Diabrotica spp. by virtue of their fumigant activity. They mayalso be useful in combating insect and acarine pests which infestdomestic animals, such as Lucilia sericata and ixodid ticks such asBoophilus spp., Ixodes spp., Amblyomma spp., Rhipicephalus spp., andDermaceutor spp. They are effective in combating both susceptible andresistant strains of these pests in their adult, larval and intermediatestages of growth, and may be applied to the infested host animal bytopical, oral or parental administration.

The following Examples illustrate various aspects of this invention. Inthe preparation Examples the products were usually identified andcharacterised by means of nuclear magnetic reasonance (NMR) spectroscopyand infra red (IR) spectroscopy. In each case where a product isspecifically named its spectral characteristics are consistent with theassigned structure. Except where stated otherwise, exemplified compoundshaving one or more asymmetrically substituted carbon atoms were preparedin racemic form.

In the Examples, Gas Liquid Chromatography (GLC) retention times weredetermined on a Hewlett Packard 5890 Gas Chromatograph, using aChrompak, CPSil 5CB column of 12.5M length and 0.2 mm internal diameter.Unless otherwise stated, the injection temperature was 100° C., and atemperature gradient of 15° C./minute employed, up to a maximumtemperature of 250° C., maintained for 4 minutes. The carrier gas washelium at a column head pressure maintained at 11 psi. Alternativeinjection and maximum temperatures are indicated in the Examples whereappropriate.

¹ H Nuclear Magnetic Resonance (NMR) spectrometry was performed at afrequency of 100 MHz on a Jeol FX 100 NMR spectrometer, unless otherwiseindicated. 90 MHz, 60 MHz, 270 MHz and 400 MHz ¹ H NMR spectrometry wereperformed using Jeol FX 90Q, Jeol PMX 60SI, Jeol FX270 and Jeol GX400spectrometers respectively.

¹⁹ F NMR spectrometry was performed on a Jeol FX90Q spectrometer at afrequency of 84.26 MHz. All NMR shift (γ) values are quoted in ppmrelative to a standard (TMS or CFCl₃).

Molecular Ion (M⁺) peaks were determined on one of three massspectrometers: Jeol DX303, Kratos MS80 or Hewlett Packard HP 5992.

The following Examples illustrates various aspects of the invention.

EXAMPLE 1

This Example illustrates the preparation of4-bromo-2,3,5,6-tetrafluorobenzaldehyde.

A stirred mixture of pentafluorobenzaldehyde (17.7 g), anhydrous lithiumbromide (8.9 g) and N-methylpyrrolidone (50 cm³) was heated at 160° C.under a nitrogen atmosphere for 2 hours, after which it was cooled andpoured into water. The solid precipitate was collected by filtration,washed on the filter with water and dried in a dessicator overphosphorus pentoxide. After trituration with diethyl ether the residualsolid was collected to yield 4-bromopentafluorobenzaldehyde (8.4 g), mp.105°-108° C.

Infra red (paraffin mull): 1700 cm⁻¹

EXAMPLE 2

This Example illustrates the preparation of4-bromo-2,3,5,6-tetrafluorobenzyl alcohol.

Sodium borohydride (1.0 g) was added portionwise over a period of 30minutes to a stirred solution of 4-bromo-2,3,5,6-tetrafluorobenzaldehyde(8.2 g) in methanol (80 cm³) whilst the temperature was maintainedwithin the range from -5° C. to +5° C., after which the mixture wasstirred for 2 hours at the ambient temperature (ca 18° C.). The mixturewas poured into water and the precipitated white solid collected byfitration, washed with water and air dried to yield4-bromo-2,3,5,6-tetrafluorobenzyl alcohol (7.5 g), mp. 60°-62° C.

Infra red (paraffin mull): 3400(b), 1500 (b) cm⁻¹

EXAMPLE 3

This Example illustrates the preparation of2-(4-bromo-2,3,5,6-tetrafluorobenzyloxy)tetrahydropyran.

Dihydropyran (3.0 g) and concentrated hydrochloric acid (0.3 cm³) wereadded successively to a stirred solution of4-bromo-2,3,5,6-tetrafluorobenzyl alcohol (8.4 g) in dry diethyl ether(50 cm³) and the mixture stirred for a further 15 hours after which themore volatile components were removed by evaporation under reducedpressure. The residual oil was confirmed by spectroscopic analysis asbeing 2-(4-bromo-2,3,5,6-tetrafluorobenzyloxy)tetrahydropyran (9.5 g) ofca 95% purity.

¹ H NMR (CDCl₃): 4.6 (m,3H); 3.9 (m,2H); 1.6 (m,6H)

EXAMPLE 4

This Example illustrates the stages in the preparation of4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol (CompoundA)

(i) Preparation of2-[4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyloxy]tetrahydropyran

n-Butyllithium (2.5 M in hexane, 2.3 cm³) was added portionwise to asolution of 2-[4-bromo-2,3,5,6-tetrafluorobenzyloxy]tetrahydrofuran (1.7g) in dry tetrahydrofuran (10 cm³) under an atmosphere of dry nitrogen,whilst the reaction temperature was maintained between -30° C. and -20°C. After 15 minutes, copper (I) bromide-dimethyl sulphide complex (1.2g) was added in one portion and the reaction temperature was maintainedat -10° C. for 1 hour, after which time 1,2-dichloroprop-2-ene (1 cm³)was added, the reaction temperature then being allowed to warm to +15°C. After 3 hours, water followed by saturated aqueous ammonium chloridesolution was added to the reaction mixture, which was then extractedinto diethyl ether. The organic layer was then washed with water andbrine, dried, and the solvent evaporated under reduced pressure. Theresidue was then subjected to medium pressure column chromatography on asilica gel column using a Gilson apparatus, eluting with petroleum ether(boiling range 30°-40° C.) containing diethyl ether (10% by volume) togive2-[4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyloxy]tetrahydropyran(1.5 g).

90 MHz ¹ HNMR (CDCl₃): 1.4-1.9 (m,6H); 3.4-4.0 (m,4H); 4.45-4.95 (m,3H);5.25 (d,2H)

Infra red (liquid film): 2950, 1630, 1470, 1260, and 1050 cm⁻¹

(ii) Preparation of 4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzylalcohol.

The tetrahydropyranyl ether prepared in stage (i) (0.2 g), was dissolvedin methanol (6 cm³), and to the stirred solution was added concentratedhydrochloric acid (several drops). After stirring for 6 hours, andstanding for a further 14 hours, the reaction mixture was poured intowater, and extracted into ethyl acetate. The organic layer was washedwith water and brine, dried, and the solvent evaporated under reducedpressure to give 4-(2-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzylalcohol as an orange oil (0.15 g).

90 MHz ¹ H NMR (CDCl₃): 1.95 (t,1H); 3.75 (s,2H); 4.8 (d,2H); 5.25(d,2H)

EXAMPLE 5

The following compounds were prepared from2-(4-bromo-2,3,5,6-tetrafluorobenzyloxy)tetrahydropyran and theappropriate halopropene by a two stage procedure similar to thatdescribed in Example 4.

(i) 4-(2-Bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol, from1,2-dibromoprop-2-ene (Compound B)

90 MHz ¹ HNMR (CDCl₃): 5.6 (d, 2H); 4.85 (d, 2H); 3.9 (s, 2H); 2.02 (t,1H).

Infra red (liquid film): 3300, 1630 cm⁻¹.

(iii) 3-(2-Fluoroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound C), from 1-iodo-2-fluoroprop-2-ene.

¹ H NMR (CDCl₃): 4.8 (s, 2H); 4.7, 4.55 (2d, 2H); 3.64 (d, 2H); 2.25-2.0(bs,1H)

(iii) EZ-4-(3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound D, E:Z ratio 2:1), from EZ-1,3-dichloroprop-2-ene (E:Z ratio2:1).

Infra red (liquid film): 3640, 1475, 1280, 1265, 920 cm⁻¹.

(iv) E-4-(3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound D, E isomer), from E-1,3-dichloroprop-2-ene.

(v) EZ-4-(3-chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound D, E:Z ratio 1:9), from EZ-1-iodo-3-chloroprop-2-ene (E:Zratio 1:9).

¹ HNMR (CDCl₃): 6.2 (d, 1H); 5.85 (q, 1H); 4.8 (s, 2H); 3.7 (d, 2H);1.95 (bs,1H)

(vi) EZ-4-(3-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound E, E:Z ratio 3:1), from EZ-1,3-di-bromoprop-2-ene (E:Z ratio3:1).

¹ H NMR (CDCl₃): 6.65, 6.2, 5,5 (3t,2H); 4.7 (s,2H); 3.4 (bs,2H)

Infra red (liquid film): 3300, 1630 cm⁻¹.

(vii) EZ-4-(3--Chloro-2-methylprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzylalcohol (Compound F, E:Z ratio 1:4), fromEZ-1-bromo-2-methyl-3-chloroprop-2-ene (E:Z ratio 1:4).

¹ H NMR (CDCl₃): 5.9 (s,1H); 4.76 (s,2H); *3.68, 3.46 (2d,2H); 2 92(s,1H); 1.8 (s,3H); *1.64 (s,3H)

* Ratio of signals 83:17

Infra red (liquid film): 3300, 1630 cm⁻¹.

(viii) 4-(3,3-Dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound G), from 1-bromo-3,3-dichloroprop-2-ene.

¹ H NMR (CDCl₃): 5.95 (t, 1H); 4.8 (s, 2H); 3.60 (d, 2H); 2.2 (s,1H)

Infra red (liquid film): 3300, 1630 cm⁻¹.

EXAMPLE 6

4-(Prop-2-yn-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol was prepared from2-[4-bromo-2,3,5,6-tetrafluorobenzyloxy)-tetrahydropyran and propargylchloride, by a two stage procedure similar to that described in Example4.

¹ H NMR (CDCl₃): 4.8 (s, 2H); 3.6 (m, 2H); 2.3 (broad s, 1H); 1.0 (t,1H).

Infra red (liquid film): 3400 cm⁻¹.

EXAMPLE 7

This Example illustrates the preparation ofE-4-(2,3-dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(Compound H, E isomer).

A solution of bromine (0.22 g) in carbon tetrachloride (10 cm³) wasadded dropwise to a stirred solution of4-(prop-2-yn-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol (0.3 g) in carbontetrachloride (10 cm³) at the ambient temperatue (ca. 22° C.). Thesolution decolourised after a short time, and analysis by gas liquidchromatography showed completion of the reaction. The solvent wasevaporated under reduced pressure to give a brown oil, which waspurified by column chromatography on a silica gel support, eluting withdichloromethane, to giveE-4-(2,3-dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol (0.5g).

¹ H NMR (CDCl₃): 5.75-5.8 (2s,1H); 4.8 (s, 2H); 3.9, 4.1 (2s, 2H);2.0-1.9 (bs,1H)

EXAMPLE 8

This Example illustrates the preparation ofE-4-(2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol,(Compound J, E isomer).

A mixture of 4-(prop-2-yn-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol (0.1g), copper (II) chloride (1.3 g), lithium chloride (0.62 g) and dryacetonitrile (23 cm³) was heated at the reflux temperature for 40 hours.The resulting dark solution was poured into dilute hydrochloric acid,and extracted into ethyl acetate. The organic phase was washed with moredilute hydrochloric acid, dried, and the solvent evaporated underreduced pressure to giveE-4-(2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol (0.1g) as an orange oil.

¹ H NMR (CDCl₃) (ppm): 4.0 (s, 2H); 4.84 (s,2H); and 6.35 (s, 1H).

Infra red (liquid film): 3400, 1490, 1285, 1055 and 820 cm⁻¹.

EXAMPLE 9

This Example describes the preparation of4-(2-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product II).

A mixture of 4-(2-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl alcohol(106 mmoles), triethylamine (106 mmoles) and dry diethyl ether wasstirred at the ambient temperature (ca. 25° C). A solution of(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylicacid chloride (106 mmoles) in dry diethyl ether was added to thereaction mixture over a period of 5 minutes; stirring was continued fora further one hour.

After removal of the solid component by filtration, the filtrate wasconcentrated by evaporation of the solvent under reduced pressure andthe residual oil subjected to purification by flash columnchromatography, on silica gel using dichloromethane as eluent, to give4-(2-bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(100 mmoles).

90 MHz ¹ HNMR (CDCl₃): 6.85 (d, 1H); 5.55 (d, 2H); 5.23 (s,2H); 3.9(s,2H); 2.3-1.9 (m,2H); 1.3 (s,6H)

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

EXAMPLE 10

This Example illustrates the preparation of4-(2-fluoroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product III).

A mixture of(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylicacid (106 mmoles), 4-(2-fluoroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzylalcohol (106 mmoles) and a catalytic amount of N,N-dimethylaminopyridinewas stirred at the ambient temperature (ca. 25° C.).N,N'-Dicyclohexylcarbodiimide (100 mmoles) was added to the reactionmixture and stirring was continued for a further 1 hour.

After removal of the solid component by filtration, the filtrate wasconcentrated by evaporation of the solvent under reduced pressure andthe residual oil subjected to purification by flash columnchromatography through silica gel using dichloromethane as eluent togive pure 3-(2-fluoroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropane-carboxylate(90 mmoles).

¹ H NMR (CDCl₃): 6.9 (d,1H); 5.25 (q,2H); 4.65 (dd, 1H, J=16Hz); 4.4;4.26 (dd,1H, J=48 Hz); 2.2 (t,1H); 1.95 (d,1H); 1.3 (s,6H).

¹⁹ F NMR (CDCl₃): -69.275; -143.59

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

EXAMPLE 11

The following compounds were prepared from the appropriate startingmaterials by the methods of Example 9 or Example 10.

(i) 4-(2--Chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product I).

90 MHz ¹ HNMR (CDCl₃) 6.90 (d, 1H); 5.3 (s,3H); 5.2 (s, 3H); 3.75 (s,2H); 2.25-1.90 (m,2H); 1.3 (s,6H)

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(ii) 4-(EZ-3--Chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 2:1) (Product IV).

90 MHz ¹ HNMR (CDCl₃): 6.9 (d, 1H); 6.2-6.75 (m,2H); 5.2 (s,2H); 3.7,3,45 (2d, 1H); 2.3-1.9 (m,2H); 1.3 (s,6H)

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(iii) 4-(E-3--Chloroprop-2-en-1-yl)-2,3,5,6-tetrafluoro, benzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product V).

¹ H NMR (CDCl₃): 6.85 (d, 1H); 5.8-6.2 (m, 2H); 5.2 (s, 2H); 3.45 (d,2H); 2.3-1.9 (m, 2H); 1.3 (s, 6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(iv) 4-(EZ-3--Chloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 1:9) (Product VI).

¹ HNMR (CDCl₃): 6.9 (d, 1H); 6.15 (d,1H); 5.85 (q, 1H); 5.2 (bs, 2H);3.7, 3.45 (2d,2H); 2.3-1.9 (m,2H); 1.3 (s,6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(v) 4-(EZ-3-Bromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 3:1) (Product VII).

¹ H NMR (CDCl₃): 6.85-6.6 (m,2H); 6.2 (m,1H); 5.2 (s,2H); 4.24 (d,2H);3.65, 3.48 (m,2H); 2.3-1.9 (m,2H); 1.3 (s,6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(vi) 4-(EZ-3--Chloro-2-methylprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(E:Z ratio of alcohol moiety 1:4) (Product VIII).

¹ HNMR (CDCl₃): 6.9 (d, 1H); 5.9 (s, 1H); 5.2 (s, 2H); 3.7, 3.5 (2s,2H); 2.3-1.9 (m, 2H); 1.8, 1.68 (2s,3H); 1.3 (s,6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(vii) 4-(3,3-Dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product IX).

¹ HNMR (CDCl₃) 6.9 (d, 1H); 5.95 (t, 1H); 5.25 (s, 2H); 3.65 (d, 2H);2.3-1.9 (m,2H); 1.3 (s,6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(viii) 4-(E-2,3-Dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product X).

¹ H NMR (CDCl₃): 6.95 (d, 1H); 6.35 (s, 1H); 5.25 (s, 2H); 4.05 (s, 2H);2.3-1.9 (m,2H); 1.3 (s,6H)

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(ix) 4-(E-2,3-dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-yl)-2,2-dimethylcyclopropanecarboxylate(Product XI).

¹ H NMR (CDCl₃): 6.9 (d, 1H); 5.6 (s, 1H); 5.2 (s, 2H); 4.1 (s, 2H);2.3-1.9 (m,2H); 1.3 (s,6H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹.

(x) 4-(E-2,3-Dibromoprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-cis-3-[(RS)-1,2-dibromo-2,2-dichloroethyl]-2,2-dimethylcyclopropanecarboxylate(Product XII).

¹ H NMR (CDCl₃): 6.6 (s, 1H); 5.4-5.0 (m, 2H); 4.1 (s, 2H); 1.9 (m, 2H);1.35 (s, 3H); 1.25 (s,3H).

Infra red (liquid film): 1730, 1650, 1630 cm⁻¹

(xi) 4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylate(Product XIII).

400 MHz ¹ HNMR (CDCl₃): 1.25 (s,3H); 1.35 (s,3H); 1.8 (d,1H); 2.45(dd,1H); 4.0 (s,2H); 5.25 (q,2H); 6.15 (d,1H); 6.35 (s,1H).

(xii) 4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl(±)-trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate(Product XV).

270 MHz ¹ HNMR (CDCl₃): 6.32 (s,1H); 5.6 (d,1H); 5.25 (s,2H); 3.99(s,2H); 2.28 (dd,1H); 1.6 (d,1H); 1.3 (s,3H); 1.19 (s,3H).

(xiii) 4-(E-2,3-dichloroprop-2-en-1-yl)-2,3,5,6-tetrafluorobenzyl2,2,3,3-tetramethylcyclopropanecarboxylate (Product XVI).

270 MHz ¹ HNMR (CDCl₃): 6.32 (s,1H); 5.19 (s,2H); 3.99 (s,2H); 1.26(s,6H); 1.18 (s,7H)

EXAMPLE 12

This Example illustrates the insecticidal properties of the products ofthis invention.

The activity of the product was determined using a variety of insectpests. The product was used in the form of liquid preparationscontaining 500 or 100 parts per million (ppm) by weight of the product.The preparations were made by dissolving the product in acetone anddiluting the solution with water containing 0.01% by weight of a wettingagent sold under the trade name "LISSAPOL" NX until the liquidpreparations contained the required concentration of the product."Lissapol" is a Registered Trade Mark.

The test procedure adopted with regard to each pest was basically thesame and comprised supporting a number of the pests on a medium whichwas usually a host plant or a foodstuff on which the pests feed, andtreating either or both the pests and the medium with the preparations.The mortality of the pests was then assessed at periods usually varyingfrom one to three days after the treatment. Details are given in TableIII.

The results of the tests are given in Table IV for each of the products,at the rate in parts per million given in the second column as a gradingof mortality designated as A, B or C wherein A indicates 80-100%mortality, B indicates 50-79% mortality and C indicates less than 50%mortality.

In Table IV the pest organism used is designated by a letter code andthe pests species, the support medium or food, and the type and durationof test is give in Table III.

                                      TABLE III                                   __________________________________________________________________________    CODE LETTERS            SUPPORT   TYPE OF                                                                             DURATION                              (Table IV)                                                                              TEST SPECIES  MEDIUM/FOOD                                                                             TEST  (days)                                __________________________________________________________________________    TUa       Tetranychus urticae                                                                         French bean                                                                             Contact                                                                             3                                               (spider mites - adult)                                                                      leaf                                                  TUe       Tetranychus urticae                                                                         French bean                                                                             Contact                                                                             3                                               (spider mites - ova)                                                                        leaf                                                  MP        Myzus persicae                                                                              Chinese   Contact                                                                             3                                               (aphids)      Cabbage leaf                                          NL        Nilaparvata lugens                                                                          Rice plant                                                                              Growth                                                                              6                                               (brown plant hopper -                                                         nymphs)                                                             HV        Heliothis virescens                                                                         Cotton leaf                                                                             Residual                                                                            3                                               (tobacco budworm - larvae)                                          DB        Diabrotica balteata                                                                         Filter paper/                                                                           Residual                                                                            3                                               (rootworm larvae)                                                                           maize seed                                            BG        Blattella germanica                                                                         Plastic pot                                                                             Residual                                                                            3                                               (cockroach nymphs)                                                  MD        Musca domestica                                                                             Cotton wool/                                                                            Contact                                                                             1                                               (houseflies - adults)                                                                       sugar                                                 __________________________________________________________________________

                                      TABLE IV                                    __________________________________________________________________________    COMPOUND                                                                              RATE                                                                  NO.     (ppm)                                                                              TUa                                                                              Tue                                                                              MP NL HV DB BG MD                                          __________________________________________________________________________    I       500  A  A  A  A  A  A  A  A                                           II      500  A  A  A  -- A  A  A  A                                           III     100  A  C  A  -- A  A  A  A                                           IV      500  A  A  A  A  A  A  A  A                                           V       500  A  A  C  -- A  A  C  A                                           VI      500  A  B  A  -- A  A  A  A                                           VII     500  A  A  A  A  A  A  A  C                                           VIII    500  A  A  A  A  A  A  A  A                                           IX      500  A  A  A  C  A  A  A  A                                           X       500  A  A  A  -- A  A  A  A                                           XI      500  A  A  A  C  A  A  A  A                                           XII     500  C  C  A  C  A  B  C  C                                           XIII    100  A  C  A   A*                                                                              A  A  A  C                                           __________________________________________________________________________     *Nilaparvata lugens replaced by Nephotettix cincticeps in this test.     

I claim:
 1. A compound of formula (I): ##STR15## wherein X represents agroup of formula: ##STR16## wherein (i) R¹ and R² are each selected fromthe hydrogen, halo and alkyl of up to four carbon atoms, or (ii) R¹ ishydrogen and R² represents either a group of formula ##STR17## or agroup of formula: ##STR18## wherein R³ and R⁴ are each selected frommethyl, halo or haloalkyl of one or two carbon atoms containing at leasttwo fluorine atoms, and Y is chloro or bromo; or X represents a group offormula: ##STR19## wherein R⁵ represents an alkyl group of up to fourcarbon atoms and Ar represents a phenyl group optionally substitutedwith one or two halogen atoms, and R, R⁶ and R⁷ are each selected fromhydrogen, halogen and alkyl of up to four carbon atoms, provided that atleast one of R, R⁶ and R⁷ represents halogen, and further provided thatR and R⁶ are not both bromine when R⁷ is hydrogen.
 2. A compound asclaimed in claim 1 having the formula (IA): ##STR20## wherein R, R⁶ andR⁷ have any of the meanings given in claim 1, and R¹ and R² are eachselected from halogen and alkyl of up to four carbon atoms, or R¹ ishydrogen and R² is a group of formula: ##STR21## wherein R³ and R⁴ areeach selected from methyl, fluoro, chloro, bromo and trifluoromethyl. 3.A compound as claimed in claim 1 wherein R, R⁶ and R⁷ have any of themeanings given in claim 1, and X represents the residue of an acid offormula X--COOH selected from the group of acidscomprising:(±)-cis-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylicacid,(±)-cis-3-[(RS)-1,2-dibromo-2,2-dichloroethyl]-2,2-dimethylcyclopropanecarboxylicacid,(±)-trans-3-(Z-2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylicacid, (±)-cis-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylicacid,(±)-trans-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylicacid and
 2. 2,3,3-tetramethylcyclopropanecarboxylic acid.
 4. Aninsecticidal and acaricidal composition comprising an insecticidally andacaricidally effective amount of a compound as defined in claim 1 inassociation with an insecticidally and acaricidally inert diluent orcarrier.
 5. A method of combating insect or acarine pests at a locuswhich comprises applying to the locus an insecticidally and acaricidallyeffective amount of a composition as defined in claim 4.